1. Field of the Invention
The present invention relates to a hybrid type working machine that is equipped with an engine and an electric power-driven motor (motor) each of that serves as the power source, and more particularly to a hybrid type working machine that is constructed so that the output of a generator that is driven by the engine may be supplied directly to the motor without the intermediary of a battery.
2. Description of the Related Art
There have in recent years been proposed so-called hybrid type working machines that use both of the engine and motor as the power source in the way that they are used as hybridization. For example, a Japanese official gazette of Japanese Patent Application Laid-Open No. 2001-161114 discloses a car type farming working machine wherein a working machine is mounted to an automotive vehicle for travel, in which to a driving system for the working machine side and that for the generator that has been loaded on the automotive vehicle for travel there is transmitted the power that is delivered from the engine. And, when the load that is applied to the engine from the working machine is small in magnitude, the generator is driven by the surplus power of the engine, and the surplus energy is accumulated in a relevant battery as the electric power. This car type farming working machine is a hybrid type working machine that attaches importance to the efficient use of energy so that the load to the engine may be maintained within a proper range of values; and that the battery may be able to be used as the source of driving the motor.
In a Japanese official gazette of Japanese Patent Application Laid-Open No. 2001-161104, there is disclosed a hybrid type managing machine (working machine) wherein for driving the travel of a managing machine main body and for driving the generator there is used an engine power, whereby the managing machine main body is driven using a motor the power source of that is a battery that has been electrically charged by the generator. This hybrid type managing machine has been improved in operating efficiency with conceiving the easy controllability of a motor enabling simplifying the complex working-machine operation mechanism.
The above-described conventional hybrid type working machine and control unit absolutely require a battery for accumulating a generated output of the generator driven by the engine. Therefore, even a small working machine cannot avoid increase in the size and weight by the same amount as a loaded battery. Particularly because if the output capacity of a generator is small, a fluctuation in power source is likely to occur due to a change in the load, the battery suppresses this fluctuation in power source. Therefore, if no battery is provided, the output is likely to be instable when the fluctuation of load is large.